Lean Sigma

Should you use Lean Manufacturing, Six Sigma or merge the two philosophies and tool sets into Lean Sigma?

Lean Manufacturing vs Six Sigma

Lean Manufacturing and Six Sigma are both business improvement philosophies that have been around now for many years; Lean manufacturing having developed out of the Toyota Production System (TPS) and Six Sigma being the invention of Motorola.

Both are heralded as being the answer to the prayers of any business, and both have their successes and their failures - fans and critics! But many businesses still ask which should I use? Should I use Lean Manufacturing or should I use Six Sigma? Which will give me the greatest benefit? Which will be easier to implement? What are they?

Lean Manufacturing

What is Lean?

Lean Manufacturing is both a philosophy and a set of tools for improving your business, based on the Toyota Production System it was introduced into the west in the 1980s. Lean is about ensuring Customer Satisfaction through delivering what they want, when they want and where they want it perfectly every time. Through the introduction of Just in Time principles and an idea called Jidoka or Automation with a human touch; Lean looks to eliminate waste from our processes.

Lean should not be approached from a waste removal perspective, it should be approached using the principles of lean identified in Womack and Jones' book the Machine that Changed the World;

Identify value as perceived by the customer

Identify the value stream

Make value flow

Pull value through the value stream

strive for perfection.

Six Sigma

What is Six Sigma?

Six Sigma originated within Motorola as their quality initiative to improve their product quality and reduce costs. Six Sigma is an expert, data driven process whereby black belts and green belts run projects focused on reducing variation to prevent defects and save money. The aim is to reduce defects to below 3.4 defects per million opportunities!

Six Sigma is heavily analytical and requires mastery of some complex statistical tools, but through the use of these tools Motorola and other pioneering companies such as General Electric ran projects that saved many millions of dollars for their companies.

What is Lean Sigma

Which should I use? Lean or Six Sigma?

Both techniques are very effective, but both have their strengths and weaknesses. Lean is very much about action and doing things NOW, better to have an 80% effective solution in place now which can be improved on over time than to wait 3 months and do nothing! Whereas Six Sigma is a methodical process of gathering data, making analysis, before taking action.

Lean is about using everyone, whereas Six Sigma is very much expert led. Lean is also focused on the customer and Six Sigma many would say is focused more on the company and its profits.

However, there is no need to choose between the two philosophies, they are not mutually exclusive, you don't have to do one and not the other! Hence Lean Sigma, a blending of the two ideas. You can use Lean's superior tools for ensuring stability and standardization such as 5S and TPM, and then improve on what you get using six sigmas statistical analysis.